How many states can a substance have, eg gas liquid, solid

Yeah there is more than just the simple 3 forms of substances!

Depends on how you define it...
I think it depends on how you define it. If you want to know how many phases of H2O there are, you get three. There are lots of different sub-phases (eight sub-phases I think), but three general states. Plasma is a material phase that is neither liquid, solid or gas, but is it H2O anymore?

There are three "common" states of matter: solid, liquid, and gas; but "common" is a misnomer because most matter in the universe is actually in a fourth state, plasma.



At a given temperature:

Solids maintain their shape and volume.

Liquids maintain their volume, but not their shape - they conform to the shape of their container.

Gases change volume and shape with pressure.

[Of course, that's not quite true as all three states can change both volume and shape somewhat. ]



Plasmas are partially ionized gasses that are, overall, electrically neutral. What "partially" is is a very grey area. There is some disagreement over whether a plasma is truly another state of matter, but it is generally recognized as one.

Bose-Einstein condensates are sometimes considered a fifth state of matter. They consist of atoms supercooled which behave as one unit rather than as separate atoms.



Heat can move you from one state to another, with an sharp increase in the amount of heat required to cross a state boundary compared to that reqired to change the temperaure within a state.



Within those states, there are subdivisions for some materials, but those aren't common from one material to another. For example, one solid state of carbon is graphite and another is diamond.

plasma

Slightly ionized = one electron in one the shells of some of the atoms, displaced to a higher energy state.
Mostly ionized = most of the atomic nuclii have all their shells of electrons stripped away. Mostly ionized occurs only at extreme temperatures and/or extreme voltage.
A third kind of ionized is when the atom has a negative charge due to one more electron than it has protons or a positive charge due to one less electron than it has protons.
Also most substances produce vapor well below the boiling point and some below the melting point. The vapor is much like gas, except errors occur, applying the gas law and vapor condenses back to liquid or solid above a certain concentration = the dew point. I think the dew point depends considerably on gases which are mixed with the vapor.
Another state of matter likely is rare except in very hard vacuum ie atomic oxygen as opposed to molecular oxygen which comes 2 atoms per molecule or ozone which comes 3 atoms per molecule. Likely all substances can be divide to single atoms, or unnatural pairs such as OH, CH, SO if widely distributed in a very high vacuum.
Reasonably white dwarf star stuff, neutronium = neutron star stuff,
quark star stuff, a bucket of neutrons and perhaps black hole stuff are different states of matter. There may be twelve or more states of matter depending on how you want to write the definitions. Neil

Has anyone remembered aqueous (symbol aq)? This is a solid dissolved in a liquid, eg salt dissolved in water. The solution would be described as aqueous.

Plasma is called the fourth state of matter. Usually, if you heat a solid, it becomes a liquid. If you heat a liquid, it becomes a gas. If you heat a gas enough, it becomes a plasma. Some solids when heated, change directly to the gaseous state whithout passing throung the liquid state. When you heat a gas to produce a plasma, it has to be hot enough that the atoms break down and the electrons are separated from the nuclei. So, it is a soup of charged particles. The electrons have a negative charge and the nuclei have a positive charge. Stars like our sun are balls of plasma. The electrons and the nuclei are always recombining. When they do, light is emitted. A fluorescent light is a mercury vapor plasma produced by a voltage across the ends. Similarly, a neon light is a neon vapor plasma.

We, in France, have plasma as fifth state.
Third being not aqueous but "colloidal".

QUESTION: What about when the pressure becomes so incredibly high
that the atoms and nuclei break down into their component particles?

Inside a black hole for instance, where gravity exceeds the escape velocities of
photons and electrons ... When those forces are breached and even nuclei
cannot exist, and collapse into their next smallest components.

Is that a "quark plasma" or something like that?





PS - Most of the mass in the universe is Dark Matter. Hmm...
Has the universe already mostly collapsed?